const int echo - 13;
const int trig - 12;
 
 int duration - 0;
 int duration - 0;

 void setup(){
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  Serial.begin(9600);
 }

void loop(){
  digitalWrite(trig, HIGH);
  delayMicroseconds(1000);
  digitalWrite(trig, LOW);

  duration-pulseIn(echo,HIGH)
  distance-[duration/2] / 28.5;
  Serial.printIn[distance];
}